Toluene and xylene are widely used as industrial solvents.
It has been well known that hippuric acid (HA) and methylhippuric acid (MHA), metabolites of toluene and xylene are excreted in the urine of persons exposed to vapors of these solvents. Therefore, the exposure of toluene and xylene can been well estimated by determining HA and MHA in the urine of workers.
The author found that HA or MHA dissolved in water-pyridine (1 : 1) solution produces a red-orange color upon addition of benzenesulfonyl chloride (BSC) at room temperature. The color has a stable absorbance maximum at 410 mμ. By adaptation of the color reaction, a direct colorimetric method for HA or MHA in the urine was designed. This method is sensitive to HA or MHA, and the result follows the Beer-Lambert Law over a wide range of concentrations. The procedure is as follows : 0.5 ml of urine containing 0.02-0.8 mg of HA or MHA per ml was pipetted into a glass tube. 0.5 ml of pyridine was added and the solution was well mixed. 0.2 ml of BSC reagent was then added and the solution was well mixed for about 5 sec by means of a thermo-mixer. The solution was allowed to stand for 30 min. at room temperature. It was then diluted to 5 ml with ethanol, and the solution was centrifuged at 2500-3000 rpm for 5 min. for removal of a little turbidity. The level of the ethanol layer was read at 410 mμ against ethanol. An aqueous solution of HA or MHA containing 0.4 mg/ml was used as the standard. Further, effect of a urinary pigment on this colorimetric method was almost negligible.

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Digital pulse wave, digital and forehead skin temperatures were examined in 286 female office workers, viz. 160 machine handlers and 126 other workers of a certain bank.
Wave forms of the digital plethysmogram were classified in six types, of which vasospastic wave and plateau wave forms, which are said to represent the spasm of peripheral vessels, were observed a little more often in the machine handlers.
Geometrical analysis of pulse wave revealed the increase of elasticity index and peripheral blood flow in the machine handlers.
In the group of machine handlers, whose duration of employment ranging from 0 to 2 years, more digital skin temperature and less skin temperature differences between forehead and finger were observed more often than in office workers. In the group whose length of employment ranging from 3 to 5 years increases of elasticity index and of peripheral blood flow were seen, and in the group whose length of employment exceeded 6 years an increase of 1/2 amplitude of the diastolic phase was revealed while it was not seen in other office workers.
Skin temperature difference between forehead and finger were more often in machine handlers.
Correlation coefficients were significant only in 1/2 amplitude of the diastolic phase and in peripheral blood flow.
Skin temperature difference between forehead and finger was smallest in the group showing, catacrotic wave form and it was greatest in the group showing plateau wave.
In brief, no remarkable difference could be observed in the finger circulation dynamics between machine handlers and other office workers, but slightly elevated resistance of finger blood flow was seen in the group of office workers, whose length of employment exceeded 3 years.

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Urinary excretion of protein, sugar and cadmium was determined on a male, 61 years old, who had been exposed for 4 years to cadmium at 0. 002 mg/m³ when he was a cadmium worker. The following results were obtained.
1) Cadmium concentration in urine was high when urine volume was small. Therefore it is desirable to determine urinary cadmium excretion per day rather than urinary cadmium concentration for the estimation of the degree of cadmium exposure.
2) Thirty-six per cent of the cadmium was daily excreted during only 4 hours in the morning, and the cadmium excretion per hour in the morning was 4 times as much as the excretion at night. Much more often urinary protein was positive in the morning. Therefore, morning urine sample was thought to be most suitable for screening cadmium poisoning.
3) Inter- and intra-daily changes of urinary cadmium excretion were significantly different at levels of 5% (coefficient of variation 35%) and 1%, respectively.
4) Biological half-lives of urinary cadmium concentration and excretion per day were 211 and 201 days, respectively.

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The spectrophotometric method reported by Commins and Lawther for estimating carboxyhemoglobin was compared with that of Kampen and others. Commins and Lawther's method proved to be valid for determining accurately low levels of carboxyhemoglobin in small blood samples. Applications of this method were done in some cases. In a study of effects of smoking on the carboxyhemoglobin levels, it has been confirmed that cigarette smoking is a major factor in determining the carboxyhemoglobin level of individuals and that this fact must always be taken into account. This method was also used in a study of the relationship between exposure to carbon monoxide and the carboxyhemoglobin levels among a group of workers, both before and after work, working in a certain underground parking station in Tokyo. This survey revealed that workers had been affected by the occupational exposure to carbon monoxide.
As a result, the method of Commins and Lawther was found to be suitable for studying the relationship of carboxyhemoglobin levels with the occupational exposure to carbon monoxide as well as with exposures to ambient air pollution.

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